Validate

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already mark readOnlyHint=true, and the description consistently describes a non-mutating lint operation. It adds meaningful behavioral detail by stating the tool reports 'concrete, located problems' and evaluates an entire checklist, including animation-level concerns, so the agent knows it will get diagnostic evidence rather than a binary pass/fail.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core behavior is stated in the first sentence, and the long checklist sentence is dense but every item maps to a real check an agent can act on. The closing guidance is memorable and earns its place by defining the tool's purpose as evidence over optimism.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only diagnostic tool with three optional parameters, the description plus a fully-covered schema and an output schema leave no major gaps: the agent knows what the tool checks, when to call it, that it is non-destructive, and that results are located reports rather than opinions.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The schema has 100% description coverage, so the baseline is 3, but the description earns an extra point by expanding the meaning of the check names into concrete concepts (off-palette colours, stray pixels, broken outlines, banding, volume drift). This helps an agent decide which subset of checks to request, even though it does not name the parameters explicitly.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Description opens with a precise verb and object: 'Lint a sprite against pixel-art rules', then enumerates the specific rule categories it checks. It clearly distinguishes itself from related siblings like preflight by framing the output as evidence-based completion assessment rather than a generic validation step.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly instructs when to run: 'Run this before telling the user a sprite is finished,' giving an unambiguous trigger. It does not name an alternative tool to use instead in other situations, so it stops short of full when/when-not guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.